Usage:
Certain parameters that affect 3176 Engine operation may be changed through electronic service tools. The parameters are stored in the ECM, NOT the personality module. Any parameter can be read, but passwords protect parameters from unauthorized changes.
The parameters fall into two catagories: System Configuration Parameters, and Customer Specified Parameters. System Configuration Parameters can be changed using an ECAP only with the proper factory passwords. Customer Specified Parameters can be changed using an ECAP or DDT only with the proper customer passwords. See the following section on passwords for more details on how to get and use passwords.
For details on how to read and change parameters using an ECAP refer to Special Instruction Form No. SEHS8886 if using the NEXG4522 Truck Engine Functions Dual Service Program Module. For the DDT refer to Special Instruction Form No. SEHS8808 Using NEXG4509 3176 Truck Functions DDT Service Program Module.
Connecting ECAP or DDT to 3176
1This is a subscription, since it is anticipated that it will be changing at regular intervals.
The Electronic Control Analyzer Programmer (ECAP) and Digital Diagnostic Tool (DDT) are powered by the 12 volts DC from the vehicle battery. This permits operation beside the engine or in the cab of a truck, which allows taking readings during vehicle operation. Use the following procedures to connect the service tool to the engine:
A. Turn KEY OFF.
B. The ECAP or DDT may be connected to the 3176 system at J8, the 9-pin Engine Data Link Connector, or at the Dash Data Link connector. Only one side of the "T" harness connector cable is used. Remove the cap on J8 and replace once testing has been completed.
NOTE: Dash Data Link Connectors may be either an 8-pin CPC or 6-pin Deutsch. See "Optional 3176 Service Tools" in section 1.0 for available adapters to Caterpillar 9-pin Deutsch Connector.
C. Connect the opposite end of the "T" cable to the ECAP or DDT.
D. Turn KEY ON to begin testing. The ECAP or DDT will operate with the engine running, or with the engine off, key on. If the ECAP or DDT does not communicate with the 3176, refer to P-320: ECAP/DDT Will Not Communicate With 3176 System.
NOTE: The ECAP/DDT may restart during engine cranking due to voltage drop.
System Configuration Parameters
System Configuration Parameters are those that affect emissions or horsepower of the engine. They are programmed at the factory and would normally never need to be changed through the life of the engine. Proper values for these parameters are stamped on the engine information ratings plate located on the valve cover or intake manifold. Factory Passwords are required to change these parameters. illustration 1 on page 27 is an example of the ECAP screen displaying System Configuration Parameters. The following is a brief description of the System Configuration Parameters:
Full Load Setting:
Number representing fuel system adjustment made at the factory to "fine tune" the fuel system. Correct value for this parameter is stamped on the engine information ratings plate.
Full Torque Setting:
Similar to Full Load Setting.
Personality Module Code:
Code which prevents use of incorrect personality module for this engine. Each horsepower family and emission certification has a different code associated with it. This code (stored in ECM) MUST match that in the personality module or a Diagnostic Code 253-02 Check Customer Or System Parameters (56) will be generated and the engine will only run at low idle. When rerating or installing a new ECM, programming this code to "0" will prompt the ECM to read and match its stored code to the personality module. Note that this code DOES NOT need to be programmed when a personality module is replaced, as long as the new module is of the same family. If the personality module is of a different family, then pistons, injectors, etc. may need to be changed and the engine information plate should also be changed to reflect the new rating.
Engine Serial Number:
Should be programmed to match the engine serial number stamped on the ratings plate. A new ECM is delivered with the engine serial number programmed to 0XX00000.
Customer Specified Parameters
Customer Specified Parameters allow a customer to restrict how a driver operates the vehicle. Some parameters may affect engine operation in ways that the inadequately trained driver does not expect. These parameters may lead to power or performance complaints, even when the engine is performing to specification.
For detailed instructions on how to program a 3176 for optimum performance and fuel economy, refer to LEKT8587, Developing Parameters For The 3176 Diesel Truck Engine.
Customer parameters may be changed repeatedly as a customer changes his operation or as new drivers are assigned to a truck. Customer Passwords are required to change these parameters. Illustration 2 on page 27 is an example of the ECAP screen displaying Customer Specified Parameters. The following is a brief description of the Customer Specified Parameters. Along with each are the minimum and maximum values for the parameter and the default value. The parameter value shown in BOLD is the programmed setting if the feature is not used.
Vehicle Speed Parameters
Vehicle Speed Cal:
Used by the ECM to scale vehicle speed reading into miles per hour. Programmed in pulses per mile. For more information refer to P-413: Vehicle Speed Calibration, in this manual.
Minimum 14,000 PPM
Maximum 65,535 PPM
Default 14,000 PPM
Vehicle Speed Limit (VSL):
Top vehicle speed the ECM will permit. The ECM will shut off fuel above this speed.
Minimum 30 mph
Maximum 127 mph and/or gear limit of truck
Default 127 mph
Engine RPM at VSL:
Maximum rpm that the engine will operate at when the vehicle speed signal reaches the programmed Vehicle Speed Limit (VSL), or when there is an ECM detected vehicle speed signal problem (the ECM will limit to this rpm when it sees no vehicle speed signal, and the engine is loaded). This is a feature to deter tampering by running without Vehicle Speed input to the ECM.
Minimum 1300 rpm
Maximum 3000 rpm
Default 3000 rpm
NOTE: When this parameter is programmed to 3000 rpm, diagnostic code 84-01, Loss Of Vehicle Speed Signal (31) is disabled, and VSL can be excluded by disconnecting the Vehicle Speed Sensor.
Cruise Control Parameters
Low Cruise Limit:
The lowest mph at which cruise can be engaged.
Minimum 15 mph
Maximum 127 mph
Default 127 mph
High Cruise Limit:
The highest mph at which cruise can be engaged.
Minimum 30 mph
Maximum 127 mph
Default 127 mph
Cruise Switch Configuration:
Defines operation of the SET/RESUME switch while it is held in position.
Default SET/ACCEL - RESUME/DECEL
Alternative SET/DECEL - RESUME/ACCEL
Engine Retarder Mode:
Defines operation of "Retarder Enable" signal while cruise switch is ON. Allowable options are: COAST or LATCH. Whe programmed to Coast, the retarder is enabled only while the service brakes are being applied. When programmed to Latch, the retarder stays enabled after the service brakes are released (a quick press of the brake pedal latches the retarder ON). The default setting is Coast. Refer to P-227: Retarder Enable Signal Test for more detail on operation of the Retarder Enable Signal Test.
PTO Governor Parameters
PTO Mode Speed Limit:
Maximum mph for PTO mode.
Minimum 1 mph
Maximum 15 mph
Default 1 mph
PTO Mode RPM Limit:
Maximum engine rpm in PTO mode.
Minimum 600 rpm
Maximum 3000 rpm
Default 3000 rpm
Progressive Shifting Parameters
Low Gears #1 RPM Limit:
Engine rpm limited below "Low Gear #1 Turn Off Speed". 3176 will hesitate at this rpm, then allow slow acceleration up to Top Engine Limit. This is to encourage the driver to shift to the next highest gear.
Minimum 1100 rpm
Maximum 3000 rpm
Default 3000 rpm
Low Gears #1 Turn Off:
Vehicle Speed where "Low Gears #1 RPM Limit" turns off. This must be matched with "Low Gear #1 RPM Limit" to the specific drive train for best performance.
Minimum 3 mph
Maximum 30 mph
Default 3 mph
Low Gears #2 RPM Limit:
Similar to "Low Gears #1 RPM Limit". Typically programmed to slightly higher rpm.
Minimum 1100 rpm
Maximum 3000 rpm
Default 3000 rpm
Low Gears #2 Turn Off:
Similar to "Low Gears #1 Turn Off". Typically programmed to a slightly higher vehicle speed.
Minimum 5 mph
Maximum 50 mph
Default 50 mph
High Gear RPM Limit:
Engine RPM Limit when vehicle speed is above "High Gear Turn On Speed". This is a "hard" limit: 3176 will not power the engine above this limit. This is to encourage the driver to shift up into overdrive or top gear.
Minimum 1300 rpm
Maximum 3000 rpm
Default 3000 rpm
High Gear Turn On Speed:
Vehicle Speed where "High Gear RPM Limit" turns on. This must be matched to the specific drive train for best performance.
Minimum 30 mph
Maximum 127 mph
Default 127 mph
Engine Parameters
Rating Number:
Number of rating within horsepower family. The Personality Module defines the horsepower family (such as 325 hp) and may contain several ratings within that family. The rating number defines which rating is used (such as 325 hp @ 1900 rpm or 325 hp @ 2100 rpm) within the family.
Top Engine Limit:
Maximum engine rpm when the engine is under load. The engine will still achieve rated rpm under no load conditions.
NOTE: TEL is dependent upon the RATING number, with some RATING numbers allowing no or little variation as specified below.
Minimum 1300 rpm
Maximum 3000 rpm
Default 1820 rpm
Low Idle RPM:
Minimum engine rpm.
Minimum 600 rpm
Maximum 750 rpm
Default 700 rpm
Idle Shutdown Time:
Time (in minutes) that engine will idle before shutting down. Engine will only shutdown if 3176 sees no engine load, no vehicle speed, and the parking brake is set. If this parameter is programmed to zero, this feature is disabled and the engine will idle until the key switch is turned OFF.
NOTE: this feature does not shut down vehicle power - the ECM and vehicle remain powered.
Minimum 3 min.
Maximum 60 min.
Default 0 min.
Vehicle ID:
Identification of the vehicle assigned by the customer. Used only for customer reference: not required by the ECM.
Engine Protection Parameters
Engine Protection Mode:
Determines the level of action taken by the ECM in response to a potentially engine damaging condition recognized by the Caterpillar Coolant Temperature, Oil Pressure, or OEM Coolant Level (if installed and enabled) Sensors.
Default WARNING
Alternative OFF
Alternative DERATE
Alternative SHUTDOWN
Coolant Level Sensor Enable/Disable:
NOTE: This feature is not available on Personality Modules for engines before OCT91. The ECAP will show NOT INSTALLED on the Customer Programmable Parameters screen for pre-OCT91 Personality Modules. If a newer Personality Module is replacing an older Personality Module, this feature must be DISABLED.
Determines if the ECM monitors the Coolant Level Sensor inputs.
Default ENABLED
Alternative DISABLED
Passwords
Factory Passwords
Factory passwords are required to perform each of the following four functions:
1. Program a New ECM
When an ECM is replaced, the System Configuration Parameters must be programmed into the new ECM. These parameters are protected by factory passwords.
2. Rerate Engine to another Engine Family
This requires changing the Personality Module Code, which is protected by factory passwords.
3. Read Customer Passwords
If the owner loses his customer passwords, he will not be able to program customer parameters. Using factory passwords, one can read customer passwords, then use those customer passwords to program customer parameters.
4. Clear Certain Diagnostic Codes
Only Diagnostic Code 190-00 (Engine Overspeed Warning) requires factory passwords to clear once it is logged. Certain other codes require customer passwords. The majority of logged codes require no passwords to clear.
Since factory passwords contain alphabetic characters, only the ECAP may perform these functions. The DDT cannot because it does not have alphabetic character keys.
To obtain factory passwords, proceed as if you already had the password. At some point, if factory passwords are truly needed, the ECAP will request factory passwords and will provide on its screen most of the information required to obtain the passwords.
Customer Passwords
Customer passwords are required to change ANY customer parameter. Customer Parameters are those that effect vehicle speed limits, horsepower rating within a family, and PTO operation. See the previous section on "Customer Specified Parameters" for more detail on what parameters are customer programmable.
Either the ECAP or DDT may change Customer Parameters (although if a customer uses alphabetic characters in his password, only the ECAP can change Customer Parameters).
To obtain customer passwords, contact the owner of the vehicle. If the owner has lost his passwords, customer passwords may be read using an ECAP (factory passwords are required in order to read the customer passwords) by following these steps:
1. Use the ECAP to access "Read/Change System Configuration Parameters", then "Read Customer Parameters".
2. When the Factory Passwords screen appears, record the information listed on the "3176 Factory Passwords Worksheet" (in this section).
3. Obtain the factory passwords. The information recorded above must be provided, and generates a permanent record at Caterpillar of the access.
4. From the Factory Passwords screen, enter the Factory Passwords.
5. When the "Read Customer Passwords" screen appears, record the Customer Passwords. The Customer Passwords may then be used to change Customer Parameters.
Programming a New ECM
The 3176 Electronic Control Module or ECM is the heart of the system. So when a problem occurs, it is easy to come to the conclusion that the ECM is responsible. That is usually the wrong conclusion. There are no moving parts inside, therefore, the ECM very seldom fails.
Most failures occur at a sensor input/output, or in the wiring and connectors. Follow the troubleshooting guide procedures, and don't replace an ECM on speculation!
However, when your troubleshooting indicates that a failure has, in fact, occurred in the ECM, the following procedure outlines the steps required to replace a faulty ECM.
ECM Replacement Procedure
1. Record customer parameters from failed ECM.
A. Obtain and record the Customer Passwords. If the customer (owner) has lost or forgotten his passwords, go to "Customer Passwords" in this section.
B. Use the ECAP to access "Read Customer Specified Parameters" from the ECM being replaced.
C. Use the "3176 Customer Specified Parameters Worksheet" (in this section), to record the customer parameters.
2. Replace the faulty ECM.
3. Obtain Factory Passwords.
A. Using the "3176 Factory Passwords Worksheet" (in this section), Record the following information from the engine information plate: Full Load Setting, Full Torque Setting, Engine Serial Number.
B. Record the mileage from the vehicle odometer.
C. Use the ECAP to access "Read/Change System Configuration Parameters". When the Factory Specified Passwords screen appears, record the following information: ECM Serial Number, Engine Serial Number, ECAP Serial Number, and Total Tattletales.
D. Leave the ECAP on the Factory Specified Passwords screen and obtain the Factory Passwords by providing the information listed on the "3176 Factory Passwords Worksheet".
4. Program the new ECM.
A. Use the ECAP to access "Read/Change System Configuration Parameters". Enter the Factory Passwords into the Factory Specified Passwords screen. Enter the Full Load Setting, Full Torque Setting, and Engine Serial Number recorded on the worksheet. Program the Personality Module Code to 0 before leaving this screen.
B. Use the ECAP to access "Read/Change Customer Specified Parameters". Enter the Customer Specified Parameters and the original Customer Passwords recorded on the worksheet.
C. Use the ECAP to access "Calibrate Sensors", and calibrate the Boost Sensor (see procedure P-225).
D. Use the ECAP to access "Calibrate Sensors", and calibrate the Engine Speed/Timing Sensor (see procedure P-221).
NOTE: If the Customer Specified Parameters are entered before the System Configuration Parameters, the Total Tattletales will change. It will then be necessary to obtain another set of Factory Passwords to access "Read/Change System Configuration Parameters".
ECAP Screen: "System Configuration Parameters"
Figure 1
ECAP Screen: "Customer Specified Parameters"
Figure 2